5.2 Relationship between diet, blood pressure, blood cholesterol and circulatory disease.

Our Diet is very important for our body systems and organs. The wrong kind of diet can cause many complications deep within the body that we are unaware of until something goes wrong.
High blood pressure, high blood cholesterol and circulatory disease can all be linked with our diets.
If our food intake was high in saturated fats then the cholesterol levels in the blood would rise. This would cause a build up of fatty deposits sticking to the artery walls and forming atheromas.
High blood pressure means that the heart is beating harder than normal to try and push the blood around the body. The walls surrounding the blood vessels will eventually be damaged and so may some organs. It also increases the risk of angina attacks, heart attacks and strokes.
High blood pressure and blood cholesterol levels can be linked together. When the arteries become hardened by the cholesterol deposits the heart becomes more strained as it has to work even harder to pump the blood through the narrow passageways of the arteries in order to reach the organs.

So diet, blood pressure and blood cholesterol are all linked together and cause circulatory disease. There are easy steps to combat this disease,
These are;

1. 30 minutes of exercise a day.
2. reduce salt intake.
3. limit alcohol intake.
4. quit smoking
5. lose excess body weight (if you are overweight)

1.2 Effective Gaseous exchange

Gaseous exchange occurs within the Alveoli in the lungs and the capillary walls.
Gaseous exchange means the diffusion of oxygen, carbon dioxide, water and other materials takes place. The oxygen diffuses through the membrane of the alveoli in to the capillaries and carbon dioxide diffuse from the capillaries into the alveoli where it is expelled from the body when expiring.
When Gaseous exchange occurs the gases only have to diffuse through two cells. These are the epithelial cell of the alveoli and the capillary wall.
In order to succeed with effective gaseous exchange a number of conditions must be met, these are large surface area and thin walls which allow the diffusion rate of the gases to be much faster,
if there is a lot of alveoli within the lungs then more gaseous exchange can occur (The alveoli can increase through exercise)
Water being diffused by surrounding calls keep the alveoli walls moist to allow effective gas exchange.
Faster diffusion rate between blood and alveoli will normally occur when the right temperature is met because it is more effective in warmer conditions.

Smoking Cessation - WHAT SMOKING DOES TO YOUR BODY

Here are the facts on smoking and the effects that it has on the body.
Smoking Cessation - WHAT SMOKING DOES TO YOUR BODY

The nervous system is affected because of the toxins inhaled from a cigerette disrupts the signals that the brain has sent to other body systems.
The respiratory systemhas reduced lung function and breathlessness because the lung airways become narrow and swell. The alveoli become permanently damaged and there is an increased risk of infections within lungs such as coughing and wheezing.
The circulatory system is affected by the tobacco smoke some of the effects are higher blood pressure and heart rate, blood becomes more prone to clotting, tightening of blood vessels, lower oxygen supply to organs and atherosclerosis.
Smokers are more prone to infections because the immune system doesn't function properly, there are lower levels of antioxidents in the blood and infections take longer to clear.
The musculorskeletal system is also affected becuse some of the muscles becomer tighter due to the toxins produced by the cigerette smoke and also bone density is reduced.

The relationship between smoking and Coronary Heart Disease (CHD)and lung cancer

Smoking is one of the factors that can trigger Coronary Heart Disease (CHD). The nicotine in a cigarette can raise blood pressure. It does this by constricting the blood vessels which will decrease the amount of blood supply to the vital organs. Nicotine can also increase the blood cholesterol levels which would normally only occur by a high fat diet.
Heart rate increases because the nervous system detects high levels of carbon monoxide in the blood. Carbon Monoxide enters the red blood cells and there is not enough room left in cell for oxygen so oxygen becomes restricted. The heart has to work harder to elliminate the toxins out of the body and supply enough oxygen to the heart and other organs. As the nervous system sends signals to the heart to make it work faster there is still not enough oxygen being received at the vital organs. The heart keeps pumping and soon it give up and cause Angina attacks or even worse a fatality.


a href="http://3.bp.blogspot.com/_MxP9XQgGOxY/S-sWp-hqFzI/AAAAAAAAADI/D4xaNWG7G28/s1600/lung+cancer.jpg">

"This is a chest x-ray of a person with bronchial cancer. This is a front view. The lungs are the two dark areas. The heart and other structures are white areas visible in the middle of the chest. The light areas that appear as subtle branches extending from the center into the lungs are cancerous.







Many people around the world suffer from lung cancer. The majority of it is related to smoking.
Many substances in a cigerette can cause damaging affects on the body and other substances make the cigerette taste nicer so its more addictive.
Cigerette smoke contains: Nicotine, Carbon Monoxide, Tar and other irritants..
Tar is the main substance that causes the cancer. The tar is made up of many different chemicals, Carcinogen is one of the main chemicals that can cause or aggravate cancer.

5.1 Describe the changes in artery structure associated with circulatory disease.

Heart disease is mainly caused by choice of lifestyle. The main offenders of this is smoking and diet.
When arteries become clogged this means that the heart will be receiving an insufficient supply of Oxygen which can lead to a condition known as Angina or even a heart attack.
Many different Arteries around the body could be subject to blockages and can affect many different organs and body parts.

picture from; http://www.nlm.nih.gov/medlineplus/ency/imagepages/18018.htm


Coronary Artery Disease (CAD) occurs when fatty deposits known as plaque build up in the artery walls allowing little or no blood to pass through. This forms a blood clot.
Too much cholesterol build up in the blood stream is one of the major causes of CAD. The plaque forms in the arteries over many years in a process called atherosclerosis. The plaque hardens in the passageways of the arteries which supply Oxygen rich blood to the major organs. Also pieces of the plaque fall of the wall of the arteries and travel in the blood stream where it can eventually block the flow of blood.

picture from:
http://www.nhlbi.nih.gov/health/dci/Diseases/Atherosclerosis/Atherosclerosis_WhatIs.html

The Arterial walls consists of the endothelium which is the inner wall that allows the blood to flow through smoothly, the media which is the muscle and elastic tissue that allows for the artery to cope with the high pressure of blood flowing through, and the adventita, this is the tough outer shell that protects the artery.

Carotid artery disease is when the arteries in both sides of the neck become blocked due to the fatty deposits clogging up on the endothelium. This causes the brain to have an insufficient supply of oxygen rich blood and can lead to stroke.

Pheripheral artery disease occurs when major arteries in the legs, arms and pelvis become blocked due to the fatt deposits. This can lead to serious infections (gangrene) or unbearable pain.

High blood pressure can damage the vessel walls because of the blood being constantly forced through them.

Some of the circulatory diseases may occur because they are heriditary i.e. high blood pressure,

These conditions can be avoided.

Redistribution of blood

When exercising the circulatory system adapts, this is because the need for more oxygen entering the muscles is important. The majority of blood during exercise flows mainly to the heart, the brain and the working muscles. The vital organs have minimal blood flow.
Arteries and Veins can either constrict or dilate during exercise as this is the most efficient way of redistributing blood. In the working muscles the arteries dilate so the increase of blood can flow through the capilleries more effectively. This means that there is an increase of Oxygen supplied and a decrease of carbon dioxide in the muscles.
The nervous system also adapts as it secretes hormones which signals the body when exercise begins. The hormones signal the the blood vessells to dilate in the heart and the working muscles.

The role of the nervous system in generating normal breathing rhythm

The heart is able to contract on its own accord but it will be unable to keep a constant rhythm of beating. This is where the Nervous system comes into effect. Impulses are sent from the brain in order to control the speeding up of the heart rate and the slowing down of the heart rate depending on it's need at a particular time.





The nervous system is critical for our every day living and functioning of the body. The Brain is divided into 3 parts, these are the Cerebrum, the Cerebellum and the brain stem. The central controlling area for breathing is situated in the lower part of the Brain stem known as the Medulla Oblongata. Also situated in the Brain stem is the Pons and the Midbrain.
It is the Brain stem along with the spinal cord and medulla oblongata that controls the autonomic functions and the transporting of nerve signals between between brain and spinal cord.(The spinal cord serves as a pathway for the nerve impulses as they travel to and from the brain.)
The autonomic nervous system sends impulses to the vital organs within our body. It functions without conscious effort and controls the heart rate, breathing rate, blood pressure and body temperature.


There are different types of neurons in the body, inspiratory neurons and expiratory neurons are responsible to maintain the normal breathing rhythm. The inspiratory neurons are active when inspiring and inactive when expiring and the expiratory neurons are active when expiring and inactive when inspiring. The neurons are sent to the diaphragm and intercostal muscles with messages signalling them to contract and relax at regular intervals.

There are two different nerve cells that detect the levels of change in oxygen and carbon dioxide. These are pheripheral chemoreceptors and central receptors. The pheripheral chemoreceptors monitor the levels of oxygen in the blood, if the oxygen decreases then they send messages to the respiratory centre to increase the rate and depth of breathing. Carbon dioxide is censored by both receptors. The central receptor is situated in the medulla. It monitors the levels of carbon dioxide in the cerebrospinal fluid. This fluid surrounds the brain and the spinal cord. If the carbon dioxide levels are too high then the receptors are triggered, they send impulses to the respiratory centre to increase the breathing rate allowing more oxygen into the blood and allowing the carbondioxide to diffuse into the capilleries so that it can exit the body.